Electrical switch and improved contact finger and contact clip construction therefor



March 22, STEPHAN ETAL ELECTRICAL SWITCH AND IMPROVED CONTACT FINGER ANDCONTACT CLIP CONSTRUCTION THEREFOR Filed July 12, 1965 2 Sheets-Sheet 120 FIG.3

INVENTORS Kurt Stephan Dayle D.Winn|e FIG.2

March 22, 1966 3,242,271

K. STEPHAN ETAL ELECTRICAL SWITCH AND IMPROVED TACT FINGER AND CONTACTFiled July 12, 1963 CLIP CONSTRUCTII THEREFOR 2 Sheets-Sheet 2 1NVENTORS Kur't Stephun Doyle D.Winn|e United States Patent 3,242,271ELECTRICAL SWlTCH AND IMPROVED CONTACT FlNGER AND CCNTACT CUPCONSTRUCTION THEREFGR Kurt Stephan and Dayle 1). Winnie, Milwaukee,Wis.,

assignors to Globe-Union Inc, Milwaukee, Win, a corporation of DelawareFiled July 12, 1%3, Ser. No. 2%,579 17 Claims. (Cl. 200-11) Thisinvention relates to switch structures and, more particularly to atuner-type switch construction.

A general object of this invention is to provide a new, improved andeconomical tuner switch construction.

Another object of this invention is to provide a switch which willprovide consistent and reliable operation, which is easy to assemble,which incorporates a minimum number of parts and which lends itselfparticularly well to automated procedures.

A further object of this invention is to provide a tuner switchconstruction wherein excellent electrical characteristics aremaintained.

For the achievement of these and other objects of this invention atuner-type switch is constructed which includes a stator and a rotormounted for rotation relative to the stator. The stator is preferablyprovided with a plurality of relatively spaced contact fingers withsuitable conductive contacts being mounted on the rotor. A contact clipis electrically and mechanically connected to each of the contactfingers, where required by the circuit, by a fused connection, e.g. aweld, and is arranged for engagement with the conductive contact duringrelative movement between the rotor and the stator. The fused connectionbetween the clips and the contact fingers provides a dependable, lowresistance electrical connection which retains its electricalcharacteristics over an extended period of time to provide a tunerswitch having an increased useful life and one which exhibits consistentoperating characteristics over that life.

In accordance with more specific aspects of this invention, the contactfingers are mounted on the stator and the conductive contact on therotor with the rotor including a contact clip which is arranged forengage ment with the contact fingers. If desired, a pair of conductivecontacts can be mounted in axial spaced relation on the rotor andcontact clips can be connected to both sides of the contact fingers forengagement with both of the conductive contacts. Furthermore, it iscontemplated that the rotor and stator be so constructed that the statorprovides a bearing for the rotor and also confines the rotor againstaxial movement in one direction relative to the stator, with one of theconductive contacts arranged to engage the stator and prevent axialmovement of the rotor in the opposite axial direction. With thisarrangement an extremely versatile, and yet simply constructed, tunerswitch construction is provided whereby various multi-level switchingarrangements are possible using the same basic elements.

To facilitate automated procedures, the conductive portions are attachedto the rotor by a heat sealed connection which permits the use of planarconductive portions and, moreover provides a dependable, long lastingconnection which is not adversely affected even by maximum environmentaltuner usage.

Another problem encountered in the use of tuner switches of the typejust outlined is the desirability of using frequency tuning screws inthe switch. Frequency tuning screws are generally threaded into thestator to provide adjustable tuning and this presents a problem in thatmaterials possessing the requisite electrical properties for use as thestator may not possess the necessary mechanical characteristics, i.e. itmay not be readily machinable. Hence, in the past there has been aconflict between the electrical and mechanical considerations involvedin the selection of the stator material and, oftentimes, the mechanicalconsiderations have placed an undue limitation on the electricalproperties of the stator. Accordingly, a further object of thisinvention is to harmonize the electrical and mechanical considerationsin stator design and selection of stator material so as to permit achoice of the stator material on the basis of the electricalconsiderations alone.

To achieve this latter object, it is contemplated to provide the statorwith frequency tuning screw receiving means which include a plurality ofinserts in the stator. The inserts are made of a readily threadablematerial and fit into molded apertures in the stator to provide anadequate anchoring media for the tuning screws without the necessity ofperforming any machining operations on the stator. In order tofacilitate handling and assembly to the stator, the inserts areconnected by a continuous band.

Other objects and advantages will be pointed out in, or be apparentfrom, the specification and claims, as will obvious modifications of theembodiment shown in the drawings, in which:

FIG. 1 is a plan view of a tuner switch;

FIG. 2 is a plan view of the opposite side of a tuner switch;

FIG. 3 is a partial enlarged section view of the tuner switch takengenerally along lines 3-3 of FIG. 1;

FIG. 4 is a plan view of the stator block;

FIG. 5 is an exploded perspective view of the rotor;

FIG. 6 is a perspective taken generally along lines 66 of FIG. 4;

FIG. 7 is a perspective view of one of the contact fingers;

FIG. 8 is a perspective view of one of the stator contact clips; and

FIG. 9 is a partial section through one of the inserts illustrating atuning screw as assembled therein.

With particular reference to the drawings, a tuner switch 10 includes astator block 12 of suitable dielectric material and a rotor assembly 14.As is perhaps most clearly illustrated in FIG. 4, the stator is agenerally planar member having a centrally located aperture 16 extendingtherethrough and rotor assembly 14 is positioned in aperture 16 forrotation relative to the stator. The stator also includes a plurality ofrelatively spaced, radially disposed slots 18 extending through thestator and opening into aperture 16. An opening 20 is provided adjacenteach of the slots 18, these openings being spaced radially from theslots 18 for a purpose which will be more fully described hereinafter.Slots 18 in stator 12 form a plurality of inwardly projecting portions22 spaced around aperture 16 which (see FIG. 6) each include anintegrally molded vertical rib 24. Ribs 24 each have a stepped innerportion defined by a horizontal shoulder 26 and a vertical edge 28which, as will be more completely described hereinafter, provide abearing for rotor assembly 14.

Slots 18 and their respective openings 20 cooperate in locating andattaching a plurality of contact fingers 30 to the stator. Moreparticularly, each of the contact fingers includes a terminal portion 34and a contact portion 3a? and are positioned on the stator at the slots18 with terminal portion 34 positioned in apertures 20 and with awedge-shaped portion 38 of the contact portion positioned betweenadjacent ones of the ribs 24. Wedge-shaped portions 38 conform generallyto the angular relationship of ribs 24 so that the contact fingers fitbetween and are held in position and against movement by the ribs. Thecontact portion 36 of the contact fingers also includes a pair of turneddown tabs 40 and 42 which are arranged to be positioned in the enlargedblind end 44 of each slot 18. With this arrangement, the contact fingersare assembled onto the stator by inserting terminal portions 34 inapertures and locating contact portion 36 between adjacent pairs of ribs24, tabs 40 and 42 are positioned in ends 44 of slots 18 and aredeformed to rigidly grip the stator and hold the contact fingers intheir assembled position. With this arrangement portions 32 extend intoaperture 16 for engagement by the rotor clips as well be described morefully hereinafter.

Turning now to FIG. 5, the rotor assembly 14 preferably includes aone-piece dielectric rotor body 48 and a pair of rotor contacts 50 and52. Non-circular projections 54 and 56 are formed at the axially opposedends of the rotor body with a non-circular aperture 58 extendingtherethrough to receive a control shaft (not shown). Mounting holes 60and 62 are formed in contacts 50 and 52 and have a shape conforming tothat of the projections 54 and 56 so that they will fit over theprojection and, when so positioned, the rotor contacts are held inposition on the rotor body.

The rotor body is also provided with nibs 64 extending from one sidethereof and nibs 66 extending from its opposite side. Nibs 64 arearranged to register with and fit into openings 68 in rotor contact 50and nibs 66 are arranged for engagement in openings 76 in rotor contact52. Nibs 64 and 66 cooperate in mounting the contacts on the rotor and,when the contacts are properly positioned on the rotor, a heat sealconnection is made to fix the contacts in position. The heat sealconnection is made by deforming nibs 64 and 66, in a manner well knownin the art, to provide heads 67 which bear against and hold the rotorcontacts to the rotor. The heat seal connection is preferred as itexceeds maximum environmental tuner requirements.

Tabs 72 and 74 are formed on rotor contacts 50 and 52 and are soarranged that, when the rotor contacts are mounted on the rotor body,they are positioned adjacent each other and can be electricallyinterconnected, for example by spot weld, or the electrical connectiontherebetween can be eliminated, if desired. Apertures 76 and 78 in rotorcontacts 50 and 52 are provided to reduce the capacitance between therotor contacts.

Rotor body 48 has, in axial cross section, a stepped configuration toprovide a flange 80 extending outwardly of a body portion 82.' In theassembled tuner switch the flange 80 of the rotor body rests on shoulder26 of ribs 24 and engages edge 28 which holds the rotor body againstradial movement so that it is confined for rotational movement inaperture 16 and relative to the stator. A plurality of stator clips 84are connected to the contact fingers (see FIGS. 2 and 3) by a spot weld,or other suitable fused joint, which has the particular advantage ofproviding an adequate mechanical connection of low electrical resistanceand one which is virtually insensitive to shock, vibration and heat andretains its desirable electrical characteristics for an indefiniteperiod thereby increasing the useful life of the tuner switch.

To increase the versatility of the tuner switch, a construction which isadaptable to multi-level switching is preferred. More particularly,rotor contacts 50 and 52 include arcuate projections 83 and 86,respectively, and, with slots 18 having been provided in the stator,contact clips can be mounted on both sides of the contact fingers.Contact clips of different lengths are used and this construction canprovide tri-level switching and is also adaptable to bi-level switchingby eliminating clips of a given length. Contact clips 84 are of uniformlength and one or more clips 84 can be used as desired and dependingupon the particular application. Clips 84 and 84 are connected to thecontact fingers on the same circumferential line, however, the length ofclips 34 is such as to only engage projections 83 and 86 of the rotorcontacts and the circuits controlled thereby can thus be opened andclosed whereas clips 84' will extend beyond these projections forcontinuous engagement with the rotor contacts. A rotor contact clip 90is connected to rotor contact 52, or to contact 50 if desired, by a spotweld 91 and, as part of the rotor assembly, is movable into selectiveengagement with portions 32 of the contact fingers. The particularswitch structure described lends itself particularly well to automatedprocedures, e.g. the connection of the contact fingers along the samecircumferential line, and still provide a highly versatile construction.The illustrated arrangement of clips 84 and 84' is merely given by wayof example and the clips, long and short, can be positioned on eitherside of the contact fingers, in any number and in any arrangement asdictated by the particular application.

FIG. 3 illustrates the preferred configuration of the stator clips. Oneof the shorter stator clips 84 is illustrated, however, it will beappreciated that the configuration of the longer clips is identical asis the configuration of rotor clip 90. Stator clips 84 are preferablyformed from a single metallic member which is stamped to providededcontact ends 102 and 104 and is then bent back on itself to align thecontact ends with each other and to form a bowed leg 106 and a leg 108which is angled toward contact 102. Contact ends 102 and 1114 are biasedtoward engagement with each other by the inherent resiliency of legs 106and 108 and when the clips, 84 and 84, are connected in the tuner, theyare arranged to receive respective ones of the rotor contacts 50 and 52between their contact ends M12 and 164 and rotor clip 90 has its contactend arranged to receive the contact fingers therebetween. Thisparticular clip configuration is preferred since it provides optimumcontact pressure and low contact resistance.

In the fabrication and assembly of the tuner switch of this invention,the contact fingers are stamped from a single sheet of material toprovide individual contact fingers 30. However, until assembly thefingers are held together at their center for ease of handling, afterassembly the central connecting section is cut away. A number of thecontact fingers are interconnected by an arcuate inductive segment 110(see FIG. 1) which is included to provide a measure of frequency tuningduring manufacture. The cont-act fingers and the inductive segment areassembled onto the stator block as was described above. Rotor contact 50is positioned on rotor body 48 and the rotor assembly assembled to thispoint is positioned in aperture 16. Rotor contact 52, with contact clip90 attached thereto is positioned on the rotor body with contact clip 90arranged for selective engagement with the contact fingers. To permitassembly, the inner end of one of the contact fingers is removed toprovide clearance for clip 90. A heat seal connection is then made bydeforming nibs 64 and 66 to provide heads 67 to hold the rotor contactsassembled on the rotor body. At this point the clips 84 and 84' can bespot welded to either one or both sides of the contact fingers and inany desired number and arrangement.

As was mentioned above inductive segment 110 pro; vides for some degreeof frequency adjustment at the factory whereby the switch is roughlyadjusted in accordance with its ultimate application. To provide forfine frequency tuning adjustment, it is common practice to provide anumber of frequency tuning screws which can be threaded into and out ofthe stator block. This has presented problems in the past in that manydielectric materials which possess the desirable electrical propertiesfor use in the stator are not readily machinable and cannot be threadedto accept the frequency screws. Hence, in the past the mechanicalrequirements of the stator block have placed a limitation on theelectrical characteristics thereof. To solve this problem it is proposedto provide a ring 112 which includes a number of hollow inserts 114which fit into apertures 116 provided in the stator block and locatedone adjacent each of the contact fingers. For ease of assembly, inserts114 are preferably interconnected by an annular ring 118 which fits intoan annular notch 120 in the stator connecting the aperture 116. Withthis arrangement ring 112 can be positioned in the stator 12 with hollowinserts 114 arranged in respective ones of the apertures. Frequencytuning screw 115 can be threaded into the insert (see FIG. 9) and in sodoing expand the insert against the walls of apertures 116 to firmlyhold the inserts in place and anchor the tuning screws on the statorwithout requiring any pre-tapping of the inserts to receive the screws.The material of stator 12 can be selected with only the electricalcharacteristics in mind and the frequency tuning screws can still beprovided since the stator can be molded with apertures 116 therein andinserts 114 used in the apertures for receipt of the frequency tuningscrews.

As will be evident from FIG. 3 the versatility of this particular tunerswitch construction is increased in that, if desired, the rotor contact50 can be eliminated and the rotor assembly 14 will still be held inposition through the combination of rotor flange 80 and rotor contact52. Furthermore, by using a combination of contact fingers 3t} and clips84 and 84 a switch construction is provided which is readily assembledwith the use of automated machinery and procedures and which stillprovides a wide variety of possible switching configurations; theconnections used in assembling the switch exceed the maximumenvironmental requirements of the tuner.

Although this invention has been illustrated and described in connectionwith particular embodiments thereof, it will be apparent to thoseskilled in the art that various changes and modifications may be madetherein without departing from the spirit of the invention or from thescope of the appended claims.

What we claim is:

1. Switch apparatus comprising, in combination, a stator of di-electricmaterial having an aperture therethrough, a plurality of contact fingersmounted on said stator in relative spaced relation, a rotor assemblysupported in said aperture for movement relative to said stator, saidrotor assembly comprising a body portion and a first contact memberconnected to said body portion, said body portion including a radiallyextending portion engaging said stator to prevent axial movement of saidbody in one direction relative to said stator and said first contactmember spaced axially from said radial portion and engaging said statorto prevent axial movement of said body portion in an opposite direction,and a plurality of first contact clips mounted on said contact fingersand arranged in the path of movement of said first contact member forselected engagement therewith.

2. The switch apparatus of claim 1 including a second contact membermounted on said body in axial spaced relation from said first contactmember and wherein said contact fingers are arranged intermediate saidfirst and second contact members, and contact clips connected to atleast one of said opposite sides thereof for selective engagement withsaid first and second contact members.

3. The switch apparatus of claim 2 including a second contact clipconnected to and movable with said first contact member, said contactfingers arranged in the path of movement of said contact clip forselective engagement with said contact fingers.

4. The switch apparatus of claim 3 wherein each of said contact clipsincludes first and second contact portions biased toward engagement witheach other and arranged to receive respective ones of said first andsecond contact members and said contact fingers therebetween forengagement therewith.

5. The switch apparatus of claim 2 wherein said first and second contactmembers include a body portion and an arcuate .portion forming a radialextension of said body portion, the points of connection of said contactclips to said contact fingers being aligned on a common circumferenceand at least one of the contact clips on the contact fingers beinglonger than the others, said one contact clip continuously engaging saidbody portion and said other contact clips arranged for selectiveengagement with said arcuate portion.

6. The combination of claim 5 wherein said stator includes means forreceiving frequency tuning members comprising a plurality of aperturesin said stator and a deformable insert positioned in each of saidapertures.

7. A tuner switch comprising, in combination, a stator of dielectricmaterial having an aperture therethrough, a plurality of relativelyspaced radially disposed slots in said stator opening into saidaperture, contact fingers fixed on said stator at said slots andextending into said aperture whereby opposite sides of said contactfingers are exposed, a rotor assembly supported in said aperture forrotation relative to said stator, said rotor assembly including a rotorbody and a pair of planar rotor contacts fixed in axial spacedrelationship on said rotor body, stator contact clips electrically andmechanically connected to said contact fingers, said contact fingersarranged intermediate said rotor contacts, and contact clips connectedto at least one of said exposed sides thereof for selective engagementwith said rotor contacts, and a rotor contact clip electricallyconnected to at least one of said planar contacts for rotation with saidrotor body and arranged for selective engagement with said contactfingers.

8. The tuner switch of claim 7 wherein said contact clips are connectedto said contact fingers by a weld joint.

9. The tuner switch of claim 8 wherein said rotor contacts include abody portion and an arcuate portion extending radially from said bodyportion and wherein said weld joints are arranged in alignment relativeto said stator and at least one of said contact clips being longer thanthe other to continuously engage said body portion with the othercontact clips arranged for selective engagement with said arcuateportion.

10. The tuner switch of claim 7 including deformable hollow members,means mounting said deformable members on said stator for receivingfrequency tuning screws, frequency tuning screws disposed in and havinga threaded engagement with said hollow members.

11. The tuner switch of claim 7 wherein said stator includes a shoulderadjacent to and extending around the periphery of said aperture and saidrotor includes a radial flange portion arranged for engagement with saidshoulder so that said shoulder provides a bearing surface for andprevents axial movement of said rotor assembly in one direction, and oneof said rotor contacts engages said stator to hold said rotor assemblyagainst axial movement in an opposite direction.

12. The tuner switch of claim 11 wherein said shoulder is defined by aplurality of ribs projecting from said stator and each positionedbetween an adjacent pair of said radial slots, said ribs having astepped configuration at the inner ends thereof for engagement with saidradial flange on said rotor.

13. A tuner switch comprising, in combination, a stator or dielectricmaterial having an aperture therethrough, a plurality of relativelyspaced radially disposed slots in said stator opening into saidaperture, contact fingers fixed on said stator at said slots andextending into said aperture whereby opposite sides of said contactfingers are exposed, a rotor assembly supported in said aperture forrotation relative to the stator, said rotor assembly comprising a rotorbody and a pair of planar contact members connected in axial spacedrelationship on said rotor body, stator contact clips electrically andmechanically connected to opposite sides of said contact fingers by afused connection, and a rotor contact clip electrically connected to atleast one of said planar contact members by a fused connection and saidcontact fingers arranged in the path of movement of said rotor contactclip for selective engagement therewith.

14. A tuner switch comprising, in combination, a stator of dielectricmaterial characterized by an aperture therethrough, a plurality ofrelatively spaced radially disposed slots in said stator opening intosaid aperture, contact fingers fixed on said stator at said slotswhereby opposite sides of said contact fingers are exposed, a rotorassembly supported in said aperture for rotation therein relative tosaid stator, said rotor assembly comprising a rotor body and a pair ofplanar contact members connected in axial spaced relationship on saidrotor body with said contact fingers, positioned therebetween, saidplanar contact members including a central body and a radial extension,stator contact clips electrically and mechanically connected to oppositesides of said contact fingers, a rotor contact clip electricallyconnected to at least one of said planar contact members and rotatablewith said rotor body, each of said contact clips characterized by firstand second arms biased toward engagement with each other and arranged sothat respective ones of said planar contact members and said contactfingers are receivable therebetween, the stator contact clips connectedto said contact fingers along a common circumferential line and arrangedin the path of movement of said planar contact radial extension forengagement therewith, at least one of said stator contact clips beinglonger than the other and arranged to continuously engage the planarcontact body.

15. In a tuner switch including a stator, a member movable relative tosaid stator, and contacts on said stator and said movable memberarranged for selective engagement therebetween upon relative movementbetween said stator and said movable member; the combination of meansfor receiving frequency tuning screws including a plurality of aperturesin said stator, deformable insert 30 means positioned in each of saidapertures, and frequency members are in the form of screws having athreaded engagement with said insert means.

References Cited by the Examiner UNITED STATES PATENTS 1,273,203 7/ 1918Thomson. 2,186,949 1/ 1940 Allison et al. 2,258,690 10/1941 Rubinstein200-15 X 2,650,960 9/ 1953 Allison 20015 2,821,580 1/1958 Black ZOO-14 X2,828,393 3/1958 Wingard 200-166 2,855,516 10/1958 Lyman et al. 334482,900,461 8/ 1959 Allison 20011 2,954,469 9/ 1960 Gelzer. 2,989,7106/1961 Gelzer et al. 3,167,852 2/1965 Stengl 20011 X KATHLEEN H. CLAFFY,Primary Examiner.

BERNARD A. GILHEANY, Examiner.

1. SWITCH APPARATUS COMPRISING, IN COMBINATION, A STATOR OF DI-ELECTRICMATERIAL HAVING AN APERTURE THERETHROUGH, A PLURALITY OF CONTACT FINGERSMOUNTED ON SAID STATOR IN RELATIVE SPACED RELATION, A ROTOR ASSEMBLYSUPPORTED IN SAID APERTURE FOR MOVEMENT RELATIVE TO SAID STATOR, SAIDROTOR ASSEMBLY COMPRISING A BODY PORTION AND A FIRST CONTACT MEMBERCONNECTED TO SAID BODY PORTION, SAID BODY PORTION INCLUDING A RADIALLYEXTENDING PORTION ENGAGING SAID STATOR TO PREVENT AXIAL MOVEMENT OF SAIDBODY IN ONE DIRECTION RELATIVE TO SAID STATOR AND SAID FIRST CONTACTMEMBER SPACED AXIALLY FROM SAID RADIAL PORTION AND ENGAGING SAID STATORTO PREVENT AXIAL MOVEMENT OF SAID BODY PORTION IN AN OPPOSITE DIRECTION,AND A PLURALITY OF FIRST CONTACT CLIPS MOUNTED ON SAID CONTACT FINGERSAND ARRANGED IN THE PATH OF MOVEMENT OF SAID FIRST CONTACT MEMBER FORSELECTED ENGAGEMENT THEREWITH.